352 E. T\,Cresson's descriptions of tico new Trigonalys. 



small and sub truncate at tip. The apical margin of segments 2 — 6 is 

 slightly emarginate in the middle. The ventral segments are entirely 



simple, and proportioned about the same as the dorsal segments, the 

 terminal one pointed, and extending slightly beyond the tip of the up- 

 per segment. The legs are long and moderately slender; the posterior 

 coxre are large and elongate, extending almost to the tip of the second 

 ventral segment. 



Trigonalys (Lycogaster) costalis. 



Male. — Black j head opaque, rather deeply and very densely punctured, cloth- 

 ed with a short, rather dense, pale pubescence, hoary in certain lights: 

 the orbits, wider in front, a spot on each side of the clypeus — which is shining 

 and feebly punctured — and upper margin of the mandibles extending down- 

 wards at the base of the teeth, yellow: palpi fuscous; antennae brown, slender, 

 about two-thirds as long as the body, 24-jointed, tip very slender. Thorax ru- 

 gosely punctured, opaque, pubescent j mesothorax with two deeply impressed. 

 longitudinal lines, converging on the scutellum: a short line on each side in 

 front of the tegulre, ending in a spot beneath the insertion of the anterior win°-s, 

 two medial abbreviated lines on the mesothorax anteriorly, tegulse, the scutel- 

 lum, except a black line down the middle, the space on each side with a spot 

 near the base of the wings, the postscutellum and a transverse line on each side, 

 an oblique spot on each side of the metathorax at tip, a narrow, oblique, indis- 

 tinct line on each side of the pleura, all yellow: metathorax finely rugose, ex- 

 cept the sides at base, which are rough and carinated longitudinally. Wings 

 hyaline, with a broad fuscous streak along the costa. nearly obsolete at the base 

 of the wing, but becoming broader toward- the tip; second submarginal cell 

 narrow, more than twice longer than wide, sub-petiolated with the first 

 discoidal cell: third submarginal subquadrate, longer than wide. Legs short; 

 posterior coxce short, scarcely attaining the middle of the first ventral segment; 

 yellowish : femora, except base and tips, dark fuscous, the intermediate pair 

 with an exterior yellowish streak : tips of posterior tibiae and of all the tarsi, 

 dusky. Abdomen short, ovate, convex, tip much incurved, pointed ; black, shin- 

 ing, closely but finely punctured : apical margin of the very small basal seg- 

 ment, yellow, as well as the more broad posterior margins of the four following 

 segments, much the broadest on the second; venter polished, the apical margin 

 of the first segment narrowly yellow and interrupted in the middle; second seg- 

 ment very large and prominent, the ti]> produced and emarginate in the middle, 

 the posterior margin with a broad yellow stripe on each side and a rounded spot 

 of the same color on the disk. Length 4^ lines ; expanse of wings 8J lines. 



Ilab.— Mass., (Hidings. Coll. Ent. Soc. Phil.) 



Should LijcoijuMi ■■>• Shuckard. be established as a valid genus, this 



species, as well as Trigonalys Gundlachii Cresson, from Cuba, should 



be classed as members of that genus. I have not yet seen a Trigonalys 



9 , but judging from the great structural differences between the two 



% specimens described above, I am inclined to believe that Lycogaster 



i> a distinct genus. 



